Sometimes it is desirable to determine the location of a mobile device, such as a cellular telephone. For example, when the mobile device places an emergency call to a public safety answering point (PSAP), the PSAP will want to know the mobile device's current location in the event the user of the mobile device is unable to provide their current location, or is otherwise incapacitated. A complication arises for mobile devices with the ability to initiate voice calls over either a cellular communication network (e.g., a third generation partnership project (3GPP) communications network, such as a global system for mobile communications (GSM) network or other wireless wide area network (WWAN)), or a wireless local area network (e.g., WLAN) using voice over IP over the WLAN. Typically, due to cost considerations, mobile device settings, and/or carrier preferences, when WLAN is available to a user, a voice call will be established and routed over the WLAN network. To determine the mobile device's location, an IP based positioning process, such as secure user plane location (SUPL), must be initiated over the WLAN network. However, many mobile device manufacturers and/or carrier networks do not support user plane positioning over the WLAN network. Thus, a positioning process initiated as a result of an emergency call would fail.